In a small bowl, mix the teaspoon of sugar into 1/2 cup (120 ml) of hand-hot water. Sprinkle the yeast on top and allow to stand for 10 minutes (if the yeast doesn’t bubble, discard and buy new yeast as it means the yeast is no longer active). Stir to combine.

Mix together the flour and sugar in a large bowl and make a well in the middle. Add the eggs as well as the yeast mixture. Warm up milk in the microwave (it should be lukewarm). Add half of the milk to the well in the flour and mix until all ingredients are combined. Add the rest of the milk and whisk until smooth.

Cover the bowl with a damp dish towel and allow to rise in a warm area for about an hour. Once the dough has doubled, stir in the salt (and fruit, if using).

Heat the oil in a large, deep pan or in a deep fryer. To check whether the oil is at the right temperature, stand the handle of a wooden spoon in the oil. If little bubbles form around it, the oil is ready.

You will need two tablespoons to form and handle the dough, as well as a slotted spoon to remove the ‘oliebollen’ from the hot oil. Quickly dip the two tablespoons into the oil and form small balls of the dough with the oiled tablespoons, carefully scraping and dropping the dough into the hot oil. The ‘oliebollen’ will sink to the bottom of the pan and then pop right back up. You should be able to fry at least 6 ‘oliebollen’ at a time, but don’t crowd the pan (see Tips below). Fry until golden brown on both sides, carefully flipping when required. Drain on a tray lined with paper towels.